St. Bonaventure teaches: “Let prudence guide your reason, let fortitude govern your temper, let temperance govern your desires, and let justice rule all your actions.” Father Geiermann writes: “All the moral virtues are subordinated to the four principal ones which are called cardinal. These four are prudence, justice, temperance, and fortitude. Each teaches a fourfold lesson. Prudence teaches us to profit by the experience of the past, to adapt ourselves to the circumstances of the present, to provide for the future, and to pause sufficiently in perplexity to clear away our doubts. Justice leads us to weigh our judgments maturely, to live lives of integrity, to respect the rights of others, and to render to every one his due. Temperance admonishes us to dispense with superfluities, to have but few wants, to avoid whatever is forbidden, and to spurn vain-glory. And fortitude warns us against pride and vain-glory in prosperity, against dejection in adversity, against taking revenge for injuries received, and against seeking a pleasant and easy life.”

Father Geiermann discusses the moral virtue of prudence in detail: “Prudence is the virtue which finds and follows the right rule of action. It judges whether a concrete action harmonizes with wisdom or truth. Though primarily a virtue of the mind, prudence not only judges of the integrity of an action, but also directs the will in avoiding evil and doing good, and so becomes the most potent of the moral virtues.” St. Bonaventure calls prudence “the guide of all virtues.” St. Augustine notes that “it teaches us to meet the present emergency, to profit by past experience, and to prepare for future contingencies.”

“The acts of prudence are: (1) avoiding sin and its voluntary occasions; (2) doing what we would advise others to do in our circumstances; (3) patient endurance of adversity; (4) maintaining self-control when suddenly placed in a critical position; (5) praying for resignation to God’s will.”

“We may fail against prudence by negligence, inconstancy, inconsiderateness, and precipitation on the one hand, and by astuteness, fraud, deception, and worldly wisdom on the other.” Father Geiermann adds: “We should use prudence in guarding against pride,” for, as St. Justin says, “He who is proud of his prudence will despise a friend and his advice and become his own enemy.”